1. Field of the Invention
The present invention relates generally to a marine propulsion transmission and, more particularly, to an actuator system that simplifies the assembly of gear case components of the transmission in which an actuator is used to move a clutch between forward, neutral, and reverse gear positions.
2. Description of the Related Art
Those skilled in the art of marine propulsion systems are familiar with many different types of transmission devices that are used for the purpose of shifting the gears of the marine propulsion device into forward, neutral, and reverse positions.
U.S. Pat. No. 3,858,101, which issued to Schmiedel et al. on Dec. 31, 1974, discloses a shift motor actuator circuit. It includes a motor driven hydraulic shift mechanism. A DC motor includes the conventional separate reverse winding and forward winding. The armature is connected to drive a valve for actuating a hydraulic shift unit.
U.S. Pat. No. 4,668,198, which issued to Nakamura on May 26, 1987, describes a power switching apparatus for outboard engines. A shifter dog is moved by a shift cam to engage with a forward gear or a reverse gear for rotating a propeller of a boat in the forward or reverse direction. A clutch mechanism is interposed between the shift rod connected to the shift cam and a clutch rod. The clutch mechanism comprises a clutch housing, the diameter of the intermediate portion of an inner opening of the housing being reduced. The housing is formed with large diameter openings at its upper and lower portions.
U.S. Pat. No. 4,698,035, which issued to Ferguson on Oct. 6, 1987, describes a marine propulsion device hydraulic system. The device comprises a shiftable transmission drivingly connecting an engine to a propeller and including a shift lever, a hydraulic shift system connected to the shift lever for actuation thereof, a hydraulic throttle assist system connected to the throttle lever for actuation thereof, and a hydraulic fluid reservoir. A pump communicates with the reservoir and a supply conduit communicates between the pump and the shift assist system. A supply conduit communicates between the shift assist system and the throttle assist system and a return conduit communicates between the throttle assist system and the reservoir.
U.S. Pat. No. 4,986,774, which issued to Wantz on Jan. 22, 1991, discloses a desmodromic shift adaptor for a counter-rotating propeller shaft assembly. The adapter member for accommodating use of a desmodromic cam actuated shifting mechanism is described. Forward thrust on the propeller shaft is transferred to the gear case at a point aft of the forward and reverse gears mounted about the propeller shaft. The adapter member includes a cup, which is adapted to mount fore one of the forward and reverse gears through a bearing member. The adapter member further includes an internal passage within which is disposed the movable cam of the shifting mechanism. An opening is in communication with the passage for allowing connection of the shift shaft to the shifting cam after assembly of the adapter member into the gear case cavity.
U.S. Pat. No. 5,470,264, which issued to Eick on Nov. 28, 1995, discloses a marine drive shift shaft mounting system. A device is provided for isolating a shift shaft extending through an exhaust passage of a bell housing in a marine drive system. The device includes an elongated sleeve for receiving the shift shaft. The sleeve has a first portion sealably mounted in a first bore extending through the top wall of the exhaust passage and a second portion sealably mounted in a second bore which extends through the bottom wall of the exhaust passage.
U.S. Pat. No. 6,176,750, which issued to Alexander et al. on Jan. 23, 2001, discloses a marine propulsion unit with a hydraulic pump. A vertical driveshaft is operably connected to the engine of the propulsion unit and carries a pinion that drives a pair of coaxial bevel gears. A hydraulically operated multi-disc clutch is actuated when engine speed reaches a preselected elevated value to operably connect the second of two bevel gears to the outer propeller shaft to thereby drive the second propeller in the opposite direction of a first propeller.
U.S. Pat. No. 6,692,320, which issued to Sawyer on Feb. 17, 2004, discloses a gear selector actuation system for a marine propulsion device. The system incorporates an adjustable motion directing component that changes the path of travel of an actuator end of a push-pull cable. This adjustable change creates a beneficial effect by changing the relative positions of a shift shaft and associated link arms in relation to positions of a wire within a sheath of a push-pull cable.
U.S. Pat. No. 6,755,703, which issued to Erickson on Jun. 29, 2004, discloses a hydraulically assisted gear shift mechanism for a marine propulsion device. The mechanism is intended for use in conjunction with a gear shift device and provides a hydraulic cylinder and a piston combination connected by a linkage to a gear shift mechanism. Hydraulic pressure can be provided by a pump used in association with either a power trim system or a power steering system. Hydraulic valves are used to pressurize selected regions of the hydraulic cylinder in order to actuate a piston which is connected, by an actuator, to the gear shift mechanism.
The patents described above are hereby expressly incorporated by reference in the description of the present invention.